Platinum certainly has come down in price, but palladium and white gold are much cheaper. Palladium costs 75 percent less and white gold is 45 percent less than platinum, said Summer Krecke, deputy editor of weddingchannel.com.

"If you are wearing the ring, no one's going to be able to tell the difference," she said.

Consider one ring

Many women are choosing a ring that can serve as an engagement ring and wedding ring, regardless of budget constraints, said Harry Glinberg, a graduate jeweler gemologist in Wauwatosa, Wis.

"Initially it's going to cost you more because you're paying for more," Krecke said. "You're really saving money in the end."

Consider a clarity-enhanced diamond

There's no such thing as a completely flawless diamond, but a clarity-enhanced diamond is 50 percent to 60 percent cheaper than a natural, nice-looking diamond, Glinberg said. On a clarity-enhanced diamond, the fractures or inclusions are filled.

Make sure a graduate gemologist looks at whatever diamond you are purchasing, Glinberg said. Unfortunately, not all jewelers are honest, and they may try to pass a clarity-enhanced diamond as natural.

Upgrade later

If you're really short on funds, purchase a cubic zirconia ring and upgrade later, Glinberg said. He advises against Mossainite, a mineral that looks similar to a diamond.

"It's less expensive than a natural diamond but still pricey for a fake diamond," he said.

He said it's better to wait and spend money on the real thing.

Go for a colored stone

Spend 10 percent of the cost of a diamond and purchase a colored stone, such as a ruby, emerald or sapphire, Glinberg said. Princess Diana chose an oval blue sapphire engagement ring, though hers was surrounded with 14 small diamonds. (It also was 18 carats.)

"They have that sparkle," said Krecke about colored stones. "If you're looking at yellow sapphires, it looks like a canary diamond."

Consider nontraditional diamonds

Krecke said she has seen a lot of brides opting for halo diamond engagement rings, with small diamonds circling a larger stone.

"It's more cost-efficient. It's timeless and it's still just as beautiful," she said.

She said raw or uncut diamonds are a great option for an individualist. A small rough- cut diamond ring costs as little as $600, she said.

"They have this really beautiful brown tone that ranges from champagne to light cognac," she said. "It really falls under this whole organic trend we're seeing."

Go for a smaller carat

There are some brides who won't be happy unless a ring is one or two carats, Krecke said. But even a slightly smaller carat can save you money at the register. Purchasing a .90-carat diamond over a 1-carat diamond can save you $1,000, she said.